The Sonoma County Board of Supervisors on Tuesday will consider zoning changes that would open up more land, including some agricultural, industrial and business parcels, to commercial-scale renewable energy projects.

The changes also would ease energy generation limits on non-commercial renewable systems installed for homes and businesses. It would lift them entirely for systems covering roofs or parking areas.

The proposed changes, which focus largely on solar systems, come as the county seeks to launch a public power agency that relies more heavily on electricity from renewable sources, including locally generated power.

The zoning changes, plus two related amendments to the county General Plan, are separate from the power agency proposal and have been in the works for several years, said Jane Riley, a county planner.

But they would help facilitate some of the power agency's goals, which call for a greater supply from a community-scale network.

Commercial systems currently are possible only on "Resource and Rural Development" lands — the largest swath of the county, taking in 395,000 acres of mostly remote pasture and timberland — and on a smaller "Public Facilities" zone. The changes would expand the permitted areas to include non-prime farmland, most of it in the 180,000 acres zoned "Land Extensive Agriculture," and in about 3,000 acres of commercial and industrial land.

The changes would not throw open the door to energy development because few of the parcels are near transmission lines, Riley said.

Still, the revisions have drawn scrutiny from farming officials concerned about the conversion of productive ag lands. The county's valley bottom vineyard lands are mostly shielded from commercial projects. Caps would limit the size of systems on non-prime farmland and rural resource land to 30 percent of the parcel, or a maximum of 50 acres.

"Initially, they said 49 percent (for the cap). We said &‘No way,' " said Tito Sasaki, president of the Sonoma County Farm Bureau.

Farmland properties protected under the tax-saving Williamson Act program would have a lower cap of 15 percent, or five acres, provided the contract allows for commercial energy projects.

Environmental advocates said large projects proposed for rural lands needed stronger public review through a General Plan change, rather than simply a use permit.

"Opening up vast areas of our county to fields of commercial solar panels by use permit only could have potentially adverse consequences," Dennis Rosatti, executive director of Sonoma County Conservation Action, wrote in a letter to the Board of Supervisors.

The changes would establish a new "Renewable Energy" zoning district under the General Plan for commercial projects.

They also would increase the output limit for non-commercial systems from 100 percent of the property's power needs to 125 percent and lift that limit entirely for rooftop and parking area systems.

You can reach Staff Writer Brett Wilkison at 521-5295 or

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